Title

Isoelectric points of multi-domain proteins

Authors

Oliviero Carugo*

Affiliation

Department of General Chemistry, University of Pavia, Viale Taramelli 12, I-27100 Pavia, Italy and Department of Biomolecular Structural Chemistry, Max F. Perutz Laboratories, Vienna University, Campus Vienna Biocenter 5, A-1030 Vienna, Austria

Email

oliviero.carugo@univie.ac.at; * Corresponding author

Article Type

Hypothesis

Date

received August 22, 2007; revised October 23, 2007; accepted November 09, 2007; published online December 05, 2007

Abstract

Although the distribution of protein isoelectric points is multi-modal, large proteins show isoelectric points less variable than small proteins and their isoelectric points tend to converge to a unique value, close to the pH of the milieu in which the proteins are functional, as far as the protein dimension increases. This study demonstrates that large proteins, which contain more than a single domain, do have isoelectric points less variable than small proteins, which contains a single domain. However, the distribution of the isoelectric points of the single domains, contained in large proteins, resembles that of small proteins, which contain a single domain. Thus, large proteins can be soluble even if their pI is very close to the pH of the milieu, in which they perform their function, since they can contain several domains, the electrostatic properties of each of which mirror those of small proteins.

Keywords

isoelectric point; domain; pH; protein

Citation

Carugo, Bioinformation 2(3): 101-104 (2007)

Edited by

P. Kangueane

ISSN

0973-2063

Publisher

Biomedical Informatics

License

This is an Open Access article which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. This is distributed under the terms of the Creative Commons Attribution License.